Ganbo appeared alongside Roma at the Auction, providing entertainment for the customers. He juggled eyeballs during the opening act and later helped restrain the victims being auctioned off. When Juuzou Suzuya began attacking the audience, he fled off-stage and joined with Uta and Roma in the neighboring building.

There, he joined in the ambush on the Hirako Squad and Shimoguchi Squad, attacking Takeomi Kuroiwa. He was briefly able to gain the upper hand, breaking Takeomi's quinque in the process and almost biting his leg off. However, the young investigator was able to overpower him and break his neck after a brief struggle.[2]